A semi-integral composite bridge of high skew

Abstract

Todwick Road Bridge in Rotherham, UK, is a single-span, road-over-rail bridge replacing the understrength existing steel and masonry arch bridge built in 1905. The new bridge forms a strategic link between the ongoing development of the former Dinnington Colliery site and the motorway network. Traffic on the bridge began to increase noticeably in late 2004, when reclamation of land at the Dinnington Colliery site was substantially complete and development of light industrial units began. It soon became apparent that this increase, while still below the expected capacity, was causing problems. It highlighted the need for a replacement scheme as early as possible. Minimising disruption to local businesses and the general public was a significant factor in the design process, which aimed to keep the duration of the road closure to the absolute minimum. For the 21·2 m effective span a 36° skew with semi-integral bankseat on a reinforced earth abutment was adopted. This choice led to some restriction in the design. The Highways Agency design guide BD 70/03 limits the design of an integral bridge on reinforced earth abutments to an 18 m span. BA 42/96 limits the design of a semi-integral bridge to a maximum of 30° skew. This paper describes the design, innovative detailing and the construction of the bridge to overcome these limitations.